Recently, with improvements in communication environments and advances in information communication techniques, service sites for providing information and/or services have been realized by using computer networks, e.g., the Internet.
Such service sites include sites for providing services to users under the condition that the users should refer to specific information such as advertisement information or access the sites using specific applications. That is, there are service sites designed to permit reference of information desired by users only after they satisfy specific procedures.
To use a service site on a computer network such as the Internet, generally, communication with a server apparatus that constructs the service site is executed using Web browser software (browser) in accordance with a protocol such as HTTP (HyperText Transfer Protocol), and the browser interprets and displays information described in a language such as HTML or XML, which is transmitted from the server apparatus whereby the user refers to the information in the service site.
Address information, e.g., URL (Uniform Resource Locator) corresponding to information that is currently being displayed is displayed on the browser. Hence, the user can register in the browser address information corresponding to information the user has finally referred to as a bookmark or make a note of the address information. If the user wants to refer to the information again, he/she can directly refer to it by directly designating the stored address information, although that information should not be referred to without predetermined operation.
To solve this problem, reference of information wanted by a user may be inhibited unless he/she acquires authentication information such as a session key by accessing the site using a predetermined URL such as a URL corresponding to the initial window of the site. In this method, however, the authentication information must be changed for every session. In addition, since session management is necessary, the load on the server apparatus increases.